Art of pressure distillation of hydrocarbon oils



Feb. 21, 1933. R. E. WILSON 1,398,414

- ART OF PRESSURE DISTILLATION 0F HYDROGARBON oILs Filed March 13, 1925 zz L REFLwr Patented Feb. 21, 1933 UNITED, @srATss \PAT ENT-f omcs ROBERT E. WILSON, OF CHICAGO, ILLINOIS, ASSIGNORIO STANDARD OIL COMPANY, 01'

' WRITING, INDIANA, A. CORPORATION-OF INDIANA Y am; or ranssuim ms'rrnmrron or nvnnocannon OILS Application filed March :13, 1925. Serial No. 15,256.

The present invention relates to improvements in the art of pressure distillation of heavier hydrocarbon oils for the production of lower boiling point products, such as gasoline. It will bvfully understood from the following description, illustrated by the accompanying drawing, in which apparatus for carrying out the invention is diagrammatically shown. V

In the apparatus illustrated, the numeral 5 indicates a diagrammatic 4 representation of a heating coil installed in asuitable furnace settm 6, and to which oil issupplied by a pump 7 suitably a surge pump, through pipe 8. From the coil 5, the heated oil passes through 'a line 9 to a drum 10, which may suitably be lagged or otherwise arranged to conserve the'heat of the oil supplied thereto. Withinthe drum 10 there are provided one'or more vertical partition walls or baffles 11 extending from near the bottom of the shell upwardly, and dividing the fluid contents of the still into s'egregatedpools 12, 13 and 13" which communicate with one another by flow through openings 11 in the lower-"portions of the baflles '11. The vapor spaces of thegseveral pools communicate above the baflles. From, the pool 12, into which the. oil

from the heating coil 5 is discharged, a return or circulating e: pipe -'14, controlled b valve 15 leads to a' small chamber 27 which communicates with the'intake of pump 7 vapor space above their out through vapor line 18 into the lower por tion of a tower19. mounted on a suitable setthrough pipe29. From the pool 13 a drawoff line 16', controlled by valve 17, is provided 'forthe discharge at unyaporizedoil. 1

Vapors evolved frolii the oil in the several pools 12, 13 and 13 collecting in the d hquid contents, pass ting 30. In the-tower 19, the vapors are cooled to condense therefrom the liquid varize'd roducts heavier than thelight boilprmlhctsdesirei; This cooling may be e ected by anydesired means, such as direct radiation from the upper part of the shell of the tower, or by supplying to the top plate of the tower, suitably through pipe21, a suit able medium, such as distillate product, raw oil-of the nature of the original stock treated,

or special feed stocks. Uncondensed products passout of the dephlegmator through vapor line 20 to any suitable condensing apparatus, preferably maintained under pressure V Reflux condensed in the tower5P-It with the nnvaporized portions manyytf the stock fed into the tower through the line 21, passes out of the bottom of the dephlegmator through line 22. The-reflux isthen preferably conducted to the chamber 27 through line .23, controlled by valve 24. Optionally, the reflux'passing .out through line 2 2-may be caused to pass, in part or wholly, through line 25, controlled by valve 26 and be discharged into thebody of oil or other suitable pools in her passes into the pool 12 in the shell 10, preferfirst passing-through coils'9, in pools 13 abl ancl 13' andca'usedto flow slowly from pool y- 12through openings 11 into pools 13' and 13!,

which are vgradually filled.- The oil is retained in the pools 12, 13 andv13, in which it is maintained at a conversion temperature, the; temperature and "-rate of flow being'controlled with respect' to'one another to cause an adequate conversion into light products of the 'desired character (such as Afterthe pools'12, 13 and 13 have vciently filled withheated oil, the valve 15 is opened, and oil from the pool12 is with Y drawn through the line -14=.to chamber 27 and circulated by pump 7 throu h the heatcoil 5, The-proportion o oil -re'-cirin cu ated maybe readily determined by the.

setting of the valve 15, andmay: suitabl be from 15 to 40% of the amount ofsto pumped through the coil.

The oil flowing from the pool 12 pools 13 and 13' is subjected therein t0' flI1 additional substantial conversion, and unasoline) i into the 4 converted oil is withdrawn through the pipe 16, its proportion being controlled by the valve 17. Vapors arising from both pools r pass into the fractionatin tower 19. At- 5 mospheric radiation may Iie used to cause fractionation of the vapors, returning substantially all the vapors heavier or of higher boiling point than the desired products. If atmospheric radiation is insufficient, or a more effective control of the cooling in the tower is desired, oil of approximately the same characteristics as the final distillate may be fed into the tower through the pipe 21 in any desired proportions, cooling the tower and, itself being vaporized and passing oflt' with the uncondensed vapors through the line 20. In some cases it is found preferable to supply raw oil to be cracked into the tower through the line 21, the oil thus supplied being preheated in the tower and passing off with the reflux as hereinafter. described. 4

The reflux condensed in the tower 19 may be conducted by the lines 22 and 23 to the 25 chamber 27, and being then forced by pump 7 through the heating coil 5 with the circulated oil supplied to the chamber 27 throu h the line 14 and such fresh oil as may e supplied through the line 28. If it is not 30 desired to return the reflux to the system through the heating coils it may be returned directly to the pool 12 through the line 25, mingling there with the heated oil supplied from the coil 5. As is readily apparent the valves 24 and 26 may be mani ulated to control the flow of the reflux. en raw oil is fed through thepi 21 into the dephlegmator the supply 0 fresh oil through the line may be correspondingly diminished or cut ofi.

The entire apparatus is preferably maintained under superatmospheric pressure, say a ressure in excess of 4 atmos.heres. The 0 in passing'through the co 5, is

heated to a conversion temperature, and referably to a temperatureof-750 to 850 at which temperature it enters the pool 12. The still 10 is lagged or thermally insulated or ma be very moderately heated, so that the oi may be retained therein for a substantial period of time at conversion temperature; in general, the drop in temperature should not be more than 75 below the entrance temperature of the heated oil. The

flow of oil through the line 14 back to the heating zone and the discharge through line 16 are so controlled that not more than 25% and preferably 10 to 15% of products boiling within the boiling range of gasoline are removed therefrom in pool 12.

Iclaim: V a

1. In the pressure distillation of oils heavier than gasoline for the production of a asoline-like products, forcing oil through a cat- 66 ing zone into a maintained pool, thereby bringing the oil to conversion temperature, discharging liquid products from said pool to anot er pool, removing oil continuously from the later pool, the oil passing from the heating zone to the first pool being led in a confined stream through the later pool in indirect heat conductive relationship with the liquid contents thereof, and forcing oil from the initial pool through the heating zone to said initial pool.

2. In the pressure distillation of oils heavier than gasoline for the production of gasoline-like products, circulating oil from a maintained pool to and through a heating zone, discharging liquid products from said pool to another pool, both said pools being maintained at conversion temperature, solely by the heat imparted to the oil circulated through the heating zone removing oil continuously from the later pool, feeding raw oil through the heating zone to the first pool, and converting from 10 to 15% of the oil fed to said first pool to gasoline-like products before leaving said pool.

3. In the pressure distillation of oils heavier than gasoline for the production of gasoline-like products, maintaining a plurality of bodies of oil and causing oil to flow successively therethrough, withdrawing oil from the first of said oil bodies, passing it together with fresh oil through a heating zone maintained at a cracking temperature, and returning it in heated state to said first oil body after first passing it in heat conductive contact with the liquid contents of a later oil body, thereby maintaining all said oil bodies at cracking temperature.

4. In the pressure distillation of oils heavier than gasoline for the production of gasoline-like products, maintaining a plurality of bodies of oil and causing oil to flow successivel therethrough, withdrawing oil from the rst of said oil bodies, passing it through a heating zone maintained at a cracking temperature, returnin it in heated state to said first oil body after rst assing it in heat conductive contact with tile liquid contents of a later oil body, thereby maintaining all said oil bodies at cracking temperature, withdrawing evolved vapors from at least one of said oil bodies and cooling said vapors to condense therefrom products heavier than the desired gasoline-like products, and passing the said condensate to the oil undergoing cracking.

5. In the pressure distillation of oils heavier than gasoline for the production of gasoline-like products, maintaining a plurality of bodies of oil and causing oil to flow successively therethrough, withdrawing oil from the first of said oil bodies, passing it through a heating zone maintained at a cracking temperature, returning it in heated state to said first oil body after first passing it in heat conductive contact with the liquid contents of a later oil body, thereby maintaining all said oil bodies at cracking temperature, withdrawing evolved vapors from at least one of said oil bodies and cooling said vapors to condense therefrom products heavier than the desired gasoline-like products, and passing the saidcondensate together with fresh oil to the oil undergoing cracking.

6. In the pressure distillation of oils heavier than gasoline for the production of gasoline-like products, maintaining a plurality of bodies of oil and causing oil to flow successively therethrough, withdrawing oil from the first of said oil bodies, passing it through a heating zone maintained at a cracking temperature, returning it in heated state to said first oil body after first passing it in heat conductive contact with the liquid contents of a later oil body, thereby maintaining all said oil bodies at cracking temperature, withdrawing evolved vapors from at least one of said oil bodies and cooling said vapors to condense therefrom products heavier than the desired gasoline-like products, and passing the said condensate through said heating zone.

7. In the pressure distillation of oils heavier than gasoline for the production of gaso line-like products, maintaining a plurality of bodies of oil and causing oil to flow successively therethrough, V withdrawing oil from the first of said oil bodies, passingit through a heating zone maintained at a cracking temperature, returning it in heated state to said first oil body after first passing it in heat conductive contact with'the liquid contents of a later oil body, thereby maintaining all said oil bodies at cracking temperature, withdrawing evolved vapors from at least one of said oil bodies and cooling said vapors to condense therefrom products heavier than the desired gasoline-like products, and passing the said condensate together with fresh oil through said heating zone.

' ROBERT E. WILSON. 

